We shall continue transmissions of human dementia material to rodents, and analyze transmissible cases in terms of clinical findings, incubation period and type and distribution of histological lesions. We shall predominantly concentrate on the following human diseases: 1) unusual dementias, 2) cases of AD with spongy changes in the neuropil and cases of CJD with AD pathology, 3) progressive infantile encephalopathies (so called "Alper's disease") and 4) dementias showing a high familial incidence of neurological disease.